Display screen or portion thereof of a device with transitional graphical user interface



FIG. 1 is a front view of a first image of a display screen or portionof a device with transitional graphical user interface;

FIG. 2 is a front view of a second image thereof;

FIG. 3 is a front view of a third image thereof;

FIG. 4 is a front view of a fourth image thereof;

FIG. 5 is a front view of a fifth image thereof;

FIG. 6 is a front view of a sixth image thereof;

FIG. 7 is a front view of a seventh image thereof;

FIG. 8 is a front view of an eighth image thereof;

FIG. 9 is a front view of a ninth image thereof; and,

FIG. 10 is a front view of a tenth image thereof.

The broken line showing of the display screen or portion thereof in allviews forms no part of the claimed design.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-10. The process or period in whichone image transitions to another image forms no part of the claimeddeign.

CLAIM The ornamental design for a display screen or portion of a devicewith transitional graphical user interface, as shown and described.